Process for preparing a food product



Patented Apr. 27, 1954 PATENT "OFFICE 2,676,889 raooass Foa PREPARING aro'on .PRODUGT 7 Burton Keenan, Kendallvill'e, iIlHL, :assignor .10 :G. R. LKFChemicaI Co. Inc.,"Huntertown, Ind.,

"'azcorporation of Indiana No Drawing. Application July 3,1953,

Serial N0."3B6,060

Failure to secure potatoes satisfactory for good chips is itself a major problem 'inthe industry when it is realized that one-common or conventional method now currently/"employedto 'condition the-potatoes requires that they be stored at "a temperature *of about seventy degrees for a period-of from three 'tof-five "weeks in order to modify their 'chet'nical structure 'so that chips made fromsuch-potatoeswill not fryunduly dark or brown. This particular method 4 of *conditioning or curing has fluctuated to "such an extent that the periodor time-ofstorage has,'in 'some -instances, progressively increased to approxi- 'mately fifteen "weeks.

subjecting enormous ouantities "of potatoes to such -a high tempera- 'ture,- or even-'a relativelylower temperature; for thisextendedperiodnaturally causes a-hi-gh per- *c'erltage of spoilage and loss resulting from s n age. In some instances decay ru thirty --pe'r'-cent. The 'costof handling such-po- '-ta'toes conditioned in accordance with this con- -='vent-iona1 method of storage and' cost of-reinoving "decayedportion's of such potatoes prior to slicing *seventyfi-ve :p'er cent thereof "will fry satis'fac- :torily.

Itis-sbelieved by manyiauthorities 'orr the'subj-ect 7 :that :different z.fungicides, insecticides and loom- ;mercial fertilizers used in connection with zthe raising of potatoes changes their chemicalastrnbture to such an extent that chips made therefrom :are unsatisfactory to 11:13.8 manufacturer becausetheyiry-dark brown.

Also, "the -:chemical constituents :ofdifferent :kindsaof potatoes :vary considerably :andazofttimes .a variance will :occur between the isamerkind rof 4 conditions .edo :not correspond.

It .is :further i'recognized -;that ''other attempts i have been :made :to :prevent :undue :browning of gpotatoi-chipsi Frorwex ample, another methodireiiquires that :the potatoes :be :Limmersedin aaroer- ,3 Glaims. (Cl. 99-100 tain -typehof conditioning solution for a period of twenty-twohours for the purpose of modifying the chemical structure of the'potatoes. Obviously, any method which necessitates immersing potatoes for this or an appreciable greater or lesser period of time could never be satisfactorily utilized on a large scale production basis because of the-vast storage tank capacity required.

It'is further knownsthat many different kinds of chemical solutions have been heretofore employed for treating whole or sliced potatoes in advance of frying. The majority of such solutions, however, havenot proven successful for the reason that they leave a bad aftertaste while other solutions cause the chips to have a rancid flavor shortly after manufacture. Moreover, some of these solutions are expensive anddifficult to utilize due to variables in timing and'heating of the solutions.

Whenall of the foregoing and other related matters are taken into consideration, it will be evident that there is La profound need :for a better novel'method or process to simplify and correct the confused conditions now existing in the industry.

Accordingly, one of the principal'objects of the subject invention is to provide a unique process or method, embodying a solution, whereby all stantially eliminated. process will permit the industry to use substanof the disadvantages above referred to are sub- More particularly, the

tia'lly all kinds of potatoes regardless of whether they are 'firsticonditioned by storage. In other :wordsythe process'has provenvequally successful in treating'newpotatoes as well as old potatoes which have been.:-st'ored at various temperatures and different periods ofrstor-age. vFor example,

if; one'lot of potatoes is stored at a temperature of thirty-five degreesfor aperiodof five-weeks and another lot at a temperatureof ififty degrees for eight -weeks,-bothlots would react or respond substantiallyalike to the same treatment. Thus,

, potatoes from different lots "or batches can be mixed together as their identity is "lost, butthe chips made from this mixture will be the same. 'A'sig'nificant object of the invention is taproviide a new process 'Wherebyuniformity of color, flavor and texture of the potato chip can be readily controlled and maintained. Chips man- 'ufactured in accordance with the invention retain their originalflavorandcrispness for along Hperiodof time and-do notbecome rancid. This isyof course, an important advantage to-the manufacturer, retailer and consumer.

ilnother object ofjtherinvention is toprovide a 3 process which can be readily used in conjunction with any of the conventional potato chip making machines or apparatus now being used by the industry.

A further object of the invention is to provide a process which is reliable, efi'icient and inexpensive.

Many other objects and advantages of the invention will become apparent after the description hereinafter set forth is considered.

Before describing in detail the solution embodied in the process or method constituting the subject invention it is believed desirable to refer briefly to the character of the conventional machines now being currently employed in manufacturing potato chips and sticks. The majority of such machines are operated on the conveyor principle and include, among other things, a unit for removing the peel, a unit for washing the whole potato or sections thereof, a slicer, a series of three separate but connected tanks through which clean water continuously circulates for washing the slices and removing excess starch and foreign matter, a spray, an inclined conveyor for draining off excess water and feeding the slices into a vat of accepted fat or vegetable shortening for frying, an inclined conveyor for draining off excess shortening or oil, a horizontal conveyor where the chips are inspected, a salter, and another conveyor from which the chips are removed for packaging. Attention is directed to the fact that considerable starchy foam generally collects and builds up in the third washing tank so it is customary to spray the slices as mentioned before they enter upon the inclined conveyor leading to the vat. The operation of such a machine is continuous so that whole or sections of raw potatoes introduced at one end of the machine are successively acted upon to produce potato chips at its other end.

The subject invention, among other things, is directed to a solution which is preferably introduced into the second of the three washing tanks for subjecting the potato slices to the solution directly after they leave the slicer. It is to be distinctly understood that insofar as the present invention is concerned the solution can be placed in any one of three tanks or in another tank constituting an additional component.

As now practiced, the solution is placed in the second tank so that the slices will be washed immediately prior to and after treatment by the solution. If the solution were placed in the third tank then it would, of course, be desirable to wash or rinse the slices prior to frying.

The constituents and amounts used in the solution are as follows:

Per cent H2O or Water 98.75 NaCl or salt 1.225 NaaCeHsOvfiHzO or sodium citrate .025

The constituents and amounts used in another solution which as proven satisfactory are as follows:

Per cent H2O or water 98.525 NaCl or salt 1.225 NasC6H5O7.5H2O or sodium citrate .25

The water, salt and sodium citrate are preferably first mixed together and then a small amount of citric acid Cal-I807 is added to establish a controlled pH of from 2.99 to 6.99. It has been determined that a pH from 4.5 to 5.5 has proven most satisfactory. Ascorbic acid in a minute amount is also preferably added to the citric acid if a more intense retarding action of browning is found necessary. It is to be understood that the percentage of the constituents may be slightly varied to accomplish the results desired, particularly in view of the fact that the hardness of the water varies in different localities.

Provision is made for preferably maintaining the solution in the second tank at a temperature anywhere between 195 degrees and 205 degrees Fahrenheit, although a range between degrees and 212 degrees may be suitable under certain conditions. The sliced potatoes are immersed in and preferably subjected to this hot solution for a period of about one minute. The immersing period may vary within a range of ten seconds to ten minutes but the one minute period has proven most satisfactory under all operating conditions. After the slices are thus treated, they are passed through a tank of clean cold water for a period of ten seconds or more. The temperature of the water in this tank may be anywhere above freezing or below boiling. The potato slices are then conveyed to a vat for frymg.

When the potato slices are subjected to the solution, the carbohydrates and proteins are attacked or inactivated by hydrolysis and/or catalytic action. The proteins break down and/or separate into various amino acids during the hydrolitic action to change the chemical structure of the chips. The chemical agents in the process break down and/or separate the proteins into amino acids which are amphoteric in nature, thus retarding the color change in the product. The above reactions plus the breakdown of the carbohydrates in the potato by'the use of a weak edible acid, such as citric or combinations of other edible acids, affords a complete control over the pH factor. The pH control of the solution is one of the governing factors of the resultant color, and the lower the pH the more intense is the retarding of the color. A pH of 6.0 down to 3.0 is practical but a pH of 5.5 down to 4.5 has proven most satisfactory. A pH of below 3.0 imparts an acid flavor which is not entirely eliminated in the subsequent washings, as used in present production methods of potato products and other farinaceous tuber products.

In addition to the foregoing it is to be understood that various forms of citrate other than sodium citrate can be utilized.

Accordingly, it should be manifest that the present invention will produce chips of an appetizing character and eye appeal to customers. More particularly, the chips have a uniform relatively white or light color and the original flavor, freshness and cripsness is retained for an exceptionally long period of time in contrast to chips manufactured prior to the advent of this invention. The process also provides chips of uniform texture and brittleness is, in some measure, eliminated.

I claim:

1. A process of treating sliced potatoes, which comprises washing the slices in a solution containing approximately 98.75% water, 1.225% of salt, .025% of sodium citrate and a small amount of citric acid to obtain a pH value from 3.00 to 6.00 for a period of anywhere between ten seconds and ten minutes at a temperature ranging between 150 degrees Fahrenheit to boiling.

2. A process of treating sliced potatoes, which comprises washing the slices in a solution containing approximately 98.75% water, 1.225% of salt, 025% of sodium citrate and a small amount of citric acid to obtain a pH value from 3.00 to 6.00 for a period of anywhere between ten seconds and ten minutes at a temperature ranging between 150 degreesj'ahrenheit to boiling, and then rinsing the slices to remove any excess solution therefrom. v

3. A process of treating sliced potatoes, which comprises washing .the slices in a solution containing approximately 98.525% water, 1.225% of salt, 25% of sodiurn' 'citrate and a small amount of citric acid to obtain a pH value from 3.00 to 6.00 for a period of anywhere between ten secends and ten minutes at a temperature ranging between 150 degrees Fahrenheit to boiling.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Grande Nov. 2, 1937 Hall May 17, 1938 Jansen Oct. 17, 1939 Johnson et al July 12, 1949 Hall et a1 June 13, 1950 Ment et a1. Jan. 29, 1952 Scalera Dec. 2, 1952 

1. A PROCESS OF TREATING SLICED POTATOES, WHICH COMPRISES WASHING THE SLICES IN A SOLUTION CONTAINING APPROXIMIATELY 98.75% WATER, 1.225% OF SALT, .025% OF SODIUM CITRATE AND A SMALL AMOUNT OF CITRIC ACID TO OBTAIN A PH VALUE FROM 3.00 TO 6.00 FOR A PERIOD OF ANYWHERE BETWEEN TEN SECONDS AND TEN MINUTES AT A TEMPERATURE RANGING BETWEEN 150 DEGRESS FAHRENHEIT TO BOILING. 